Valves closed but regs pressurised?

[grantmac]

Sidemount:
Off and purged until they go on. Partially to save TX battery, partially so I can leave them on the beach without worry that there will be a gas loss.
Anything in the water will be pressurized, off if not breathable.

 

[tursiops]

Thank you, so it appears that what I’m doing doesn’t sound too bad if I understood you correctly (keep valves shut when not in use after setting up, but keep regs pressurised).

Turning the valves off does not turn off the transmitters; they measure what is in the first stage, which you are keeping pressurized.

 

[NothingClever]

Tank valves on/off and regs pressurised: what’s the standard way during predive?

For example when diving backmount twinset with deco bottle, I first analise backgas and deco gas, screw in the first stages, open the tank valves, and check that the regs and spg are working (for the regs I take a quick breath, not just pushing the purge button), then close the valves (both twinset and deco bottle) but leave all the regs pressurised.

The gear is then transported to the boat, and I get ready.
Once on the boat and before jumping into the water I will do my routine which involves turning the twinset valves open and do another quick check of the regulators
For the deco bottle I will reopen the valve, check the reg (still by doing a quick breath, usually with the reg still tucked in), and turn the valve shut without purging the reg (I will reopen the valve only during gas switch underwater).

Postdive I will turn all the valves off and purge the regulators before unscrewing them from the tanks.

Is that the normal way?

I think your approach is sound.

The one extra step I take is a quick open of my deco bottle valves to ensure the line is still charged and didn’t burp off any pressure while splashing.

 

[broncobowsher]

Saving transmitter batteries is a horrible reason. They last so long anyway. Plenty of stories of people leaving them on for weeks and not killing them. Even if it is a couple hours for a boat ride, that's nothing.

 

[johndiver999]

Saving transmitter batteries is a horrible reason. They last so long anyway. Plenty of stories of people leaving them on for weeks and not killing them. Even if it is a couple hours for a boat ride, that's nothing

Leaving your tanks on during a boat ride is a stupid idea. It is very easy for gear to get slammed around, a purge button gets partially depressed and you lose a bunch of air, since you can't hear anything as the boat is pounding into the seas.

 

[broncobowsher]

Leaving your tanks on during a boat ride is a stupid idea. It is very easy for gear to get slammed around, a purge button gets partially depressed and you lose a bunch of air, since you can't hear anything as the boat is pounding into the seas.

Didn't saw that was a bad idea. Just that 'saving the batteries' isn't a valid argument.

 

[Bump_Head]

Slightly off from your original question about pre-dive however: I would commonly have all tanks with the exception of primaries, charged and off. Done during pre-dive checks. I recently dove with a tech team that insisted on all non- primary tanks be charged and “on” due to the possibility of missing a leak during the bubble check. It’s definitely erring on the side of safety but it’s something I’ve started to incorporate. Once at depth I close the tanks (saves continuous charging on the descent).

 

[LFMarm]

Once at depth I close the tanks (saves continuous charging on the descent).

What do you mean?

 

[Bump_Head]

What do you mean?

Boyle’s Law
In order to avoid a wet first breath on charges regs, I feather the valve on/off on descent.

 

[johndiver999]

Boyle’s Law
In order to avoid a wet first breath on charges regs, I feather the valve on/off on descent.

How does wet breathing relate to the pressure in the lp hose of second stage?